WO2013061844A1 - Electrolyte solution for non-aqueous secondary battery, and secondary battery - Google Patents

Abstract

An electrolyte solution for a non-aqueous secondary battery, the electrolyte solution containing in an organic solvent an electrolyte and at least one cyclopropane compound selected from among a compound represented by formula (I-1), a compound represented by formula (II-1), and a compound represented by formula (III-1). (In the formulae, R¹¹ to R¹⁵, R²¹ to R²⁴, and R³¹ to R³⁴ represent a hydrogen atom or a specific substituent. L¹¹, L²¹, L³¹, and L³² represent a specific linking group. X represents an electron-attractive group, and n and m each independently represent 1 or 2.)

Description

Non-aqueous secondary battery electrolyte and secondary battery

The present invention relates to an electrolyte for a non-aqueous secondary battery containing an organic solvent, and a secondary battery using the same.

Recently, secondary batteries called lithium ion batteries, which are attracting attention, use secondary batteries (so-called lithium ion secondary batteries) that use insertion and extraction of lithium in charge and discharge reactions, and precipitation and dissolution of lithium. They are roughly classified into secondary batteries (so-called lithium metal secondary batteries). These can obtain a large energy density as compared with lead batteries and nickel cadmium batteries. In recent years, using this characteristic, it has become widespread as a power source for portable electronic devices such as a camera-integrated VTR (video tape recorder), a mobile phone, or a notebook computer. Along with this, development of lithium ion secondary batteries that are particularly lightweight and capable of obtaining a high energy density has been underway. Further, there is a strong demand for miniaturization, weight reduction, long life, and high safety.

As an electrolytic solution of a lithium ion secondary battery or a lithium metal secondary battery (hereinafter collectively referred to simply as a lithium ion secondary battery), the conductivity is high and the potential is stable. A combination of a carbonate ester solvent such as propylene carbonate or diethyl carbonate and an electrolyte salt such as lithium hexafluorophosphate is widely used.

As an example of improving the components of the electrolytic solution, there is one in which a specific cyclic compound is applied in order to suppress an increase in internal resistance at a high temperature (80 ° C.) (see Patent Document 1). In addition, in a special cell in which a film of polyvinylidene fluoride is formed on an electrode, there is one that can suppress gas generation at the time of discharge by adding an acid anhydride to an electrolytic solution (see Patent Document 2). ).

JP 2007-265858 A Japanese Patent Laid-Open No. 2001-155572

According to the confirmation of the present inventors, when considering the improvement in the performance of secondary batteries, which has been increasing more and more recently, the technology of the above-mentioned patent document is still not sufficient (see the comparative example described later), and comprehensive evaluations in a plurality of evaluation items. High performance was desired.
The present invention has been made in view of such problems, and exhibits high performance in terms of cycle characteristics and low-temperature discharge rate, and is also excellent in high-temperature storage properties related to the positive electrode characteristics (and, if necessary, high-speed charge / discharge characteristics). It aims at provision of the electrolyte solution for secondary batteries, and a secondary battery.

The above problem has been solved by the following means.
[1] Selected from the group consisting of an electrolyte, a compound represented by the following formula (I-1), a compound represented by the following formula (II-1), and a compound represented by the following formula (III-1) The electrolyte solution for non-aqueous secondary batteries which contains the at least 1 sort (s) or more of cyclopropane compound in an organic solvent.

(In the formula (I-1), R ¹¹ to R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. R ¹⁵ has 1 carbon atom. Represents a substituent that may contain an oxygen atom, a nitrogen atom, or a sulfur atom of ˜7, L ¹¹ represents an alkylene group or a carbonyl group, and X represents an electron demand that indicates a value of 0 or more in the σp value of Hammett's rule. Represents an attractive group.)
(In the formula (II-1), R ²¹ to R ²⁴ each independently represents a hydrogen atom or a substituent. L ²¹ represents an atomic group forming a ring structure together with the carbon atom of the carbonyl group and cyclopropyl group in the formula Represents.)
(In the formula (III-1), R ³¹ to R ³⁴ each independently represents a hydrogen atom or a substituent. L ³¹ represents an oxygen atom, —NR ³⁵ —, or a carbonyl group. L ³² represents an alkylene group. Represents an oxygen atom, a sulfur atom, —SO ₂ —, or —NR ³⁵ —, R ³⁵ represents an alkyl group or an aryl group, and n and m each independently represent 1 or 2.)
[2] The electrolyte solution for a nonaqueous secondary battery according to [1], wherein the substituent X in the formula (I-1) represents a cyano group, an alkoxycarbonyl group, or a carbamoyl group.
[3] The electrolyte solution for a nonaqueous secondary battery according to [1] or [2], wherein R ¹¹ to R ^{14 in} formula (I-1) are hydrogen atoms.
[4] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [3], wherein X in the formula (I-1) is a cyano group.
[5] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [4], wherein -L ¹¹ -R ^{15 in the} formula (I-1) is represented by -COOR ¹⁶ .
^{(R 16} is, a carbonyl group (-CO-), an ether group (-O-), a or an imino group ^{(-NR 17} - ^{.R 17} representing a) alkyl groups of 1-6 carbon atoms which may be interposed in Represents a hydrogen atom or an alkyl group.)
[6] The ring formed by L ²¹ in formula (II-1) contains —CONR ²⁵ — (wherein R ²⁵ represents an alkyl group or an aryl group) or —COO—. Secondary battery electrolyte.
[7] The electrolyte solution for a non-aqueous secondary battery according to [1] or [6], wherein the compound represented by the formula (II-1) is a compound represented by the following formula (II-2).

(Wherein R ²¹ to R ²⁴ have the same meaning as in formula (II-1). L ²² represents an atomic group forming a ring structure together with the carbon atoms of two carbonyl groups and a cyclopropyl group in the formula. )
[8] The ring formed by L ²¹ in formula (II-1) or the ring formed by L ²² in formula (II-2) is a 5-membered or 6-membered ring [1], [6], and [7 ] The electrolyte solution for non-aqueous secondary batteries of any one of.
[9] The linking group formed by (L ³¹ ) n in formula (III-1) is a carbonyloxy group, an amide group, or —COR ³⁶ — (R ³⁶ represents an alkylene group having 1 to 3 carbon atoms). [1] The electrolyte solution for a non-aqueous secondary battery.
[10] The electrolyte solution for a non-aqueous secondary battery according to [1] or [9], wherein L ³² in formula (III-1) is an alkylene group, an oxygen atom, a sulfur atom, or —NR ³⁵ —.
[11] Any one of [1], [9], and [10], wherein the compound represented by the formula (III-1) is a compound represented by the following formula (III-2) or (III-3) The electrolyte solution for non-aqueous secondary batteries of 1 item | term.

(Wherein R ³¹ to R ³⁴ and L ³² have the same ^meaning as in formula (III-1).)
[12] The electrolysis for nonaqueous secondary battery according to any one of [1] and [9] to [11], wherein L ³² in the formula (III-1) is an alkylene group having 1 to 3 carbon atoms. liquid.
[13] The electrolyte for a nonaqueous secondary battery according to any one of [1] and [9] to [12], wherein L ³² in formula (III-1) is a methylene group.
[14] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [13], wherein the electrolyte is a lithium salt.
[15] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [14], wherein the cyclopropane compound is applied in the range of 0.005 to 20% by mass with respect to the total amount of the electrolyte solution.
[16] The electrolyte solution for a non-aqueous secondary battery according to any one of [1] to [15], wherein a cyclic carbonate, a chain carbonate, or a cyclic ester is employed as the organic solvent.
[17] A lithium secondary battery comprising the nonaqueous secondary battery electrolyte solution according to [1] to [16], a positive electrode, and a negative electrode.
[18] The secondary battery according to [17], wherein lithium titanate is applied as an active material for the negative electrode.
[19] A kit for an electrolyte solution for a non-aqueous secondary battery using a mixture of a first agent and a second agent,
Nonaqueous secondary battery in which the first agent contains an electrolyte and the second agent contains a cyclopropane compound represented by the following formula (I-1), formula (II-1), or formula (III-1) Electrolytic solution kit.

(In the formula (I-1), R ¹¹ to R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. R ¹⁵ has 1 carbon atom. Represents a substituent that may contain an oxygen atom, a nitrogen atom, or a sulfur atom of ˜7, L ¹¹ represents an alkylene group or a carbonyl group, and X represents an electron demand that indicates a value of 0 or more in the σp value of Hammett's rule. Represents an attractive group.)
(In the formula (II-1), R ²¹ to R ²⁴ each independently represents a hydrogen atom or a substituent. L ²¹ represents an atomic group forming a ring structure together with the carbon atom of the carbonyl group and cyclopropyl group in the formula Represents.)
(In the formula (III-1), R ³¹ to R ³⁴ each independently represents a hydrogen atom or a substituent. L ³¹ represents an oxygen atom, —NR ³⁵ —, or a carbonyl group. L ³² represents an alkylene group. Represents an oxygen atom, a sulfur atom, —SO ₂ —, or —NR ³⁵ —, R ³⁵ represents an alkyl group or an aryl group, and n and m each independently represent 1 or 2.)

The electrolyte solution for non-aqueous secondary battery and the secondary battery using the same of the present invention exhibit high performance in cycle characteristics and low-temperature discharge rate, and also have high-temperature storage characteristics related to the positive electrode characteristics (including rechargeability if necessary). Also excellent.
The above and other features and advantages of the present invention will become more apparent from the following description and accompanying drawings.

It is sectional drawing which models and shows the mechanism of the lithium ion secondary battery which concerns on embodiment of this invention. It is sectional drawing which shows typically the specific structure of the lithium ion secondary battery which concerns on preferable embodiment of this invention. Test No. of Example It is a graph which shows the discharge curve of II-301 and II-c32. Test No. of Example It is a graph which shows the discharge curve of III-301 and III-c32.

Hereinafter, preferred embodiments I to III of the present invention will be described respectively. The embodiments I to III share the same or corresponding special technical features and constitute a single general inventive concept.
<Embodiment I>
In the nonaqueous electrolytic solution of the present embodiment, a specific cyclopropane compound is contained in the electrolytic solution. Thereby, when it applies to a secondary battery, various performance can be improved and also the load characteristic in a positive electrode can be improved. The reason for this is not clear, but is estimated as follows. The cyclopropane compound used in this embodiment has a specific substituent X. This group has the property of attracting electrons, and by its action, it is considered that the cyclopropane ring is moderately easily opened, and the production of a polymer having a good action at or near the electrode surface is promoted. Furthermore, it is presumed that a specific substituent (—L ¹¹ —R ¹⁵ ) substituted with the same carbon atom as these groups also functions favorably and improves the electrode characteristics of the positive electrode as well as the negative electrode. The That is, when the cyclopropane ring of the specific cyclopropane compound is opened, a polymer having a more desirable form for the positive electrode and the negative electrode is formed to form SEI (Solid Electrolyte Interface), which has led to the improvement of the above performances in the secondary battery. Conceivable.

[Compound represented by Formula (I-1)]
The electrolyte solution for a non-aqueous secondary battery of this embodiment contains a specific cyclopropane compound represented by the following formula (I-1).

・ R ¹¹ to R ¹⁴
In the formula, R ¹¹ to R ¹⁴ each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. Specific examples of the alkyl group, aryl group, and alkoxy group include the examples of the substituent T described below. R ¹¹ to R ¹⁴ may be bonded to each other or condensed to form a ring structure. R ¹¹ to R ¹⁴ may further have a substituent, and examples of the substituent include the substituent T described later.
Among these, it is particularly preferable that R ¹¹ to R ¹⁴ are hydrogen atoms.

・ R ¹⁵
R ¹⁵ represents a substituent having 1 to 7 carbon atoms, preferably a substituent having 1 to 5 carbon atoms. R ¹⁵ may be a hydrocarbon substituent consisting only of carbon atoms and hydrogen atoms, but may be a substituent containing O, N, or S. R ¹⁵ may be linear or branched, and may be cyclic or linear. R ¹⁵ may be composed only of a saturated bond or may have an unsaturated bond. When it is cyclic, it may be an aromatic ring, an aliphatic ring, an aromatic heterocyclic ring, or an aliphatic heterocyclic ring. When R ¹⁵ contains O, N, or S, examples of the atomic group containing O include an ether group (—O—), a carbonyl group (—CO—), and a carbonyloxy group (—COO—). Examples of the atomic group containing N include an imino group (—NR ¹⁷ —: R ¹⁷ is a hydrogen atom or an alkyl group, and a preferred range will be described later), an amide group (—CONR ¹⁷ —), and the like. Examples of the atomic group containing S include a thioether group (—S—), a thiocarbonyl group (—CS—), —CSO—, and —CSS—.

・ L ¹¹
L ¹¹ represents an alkylene group (preferably having 1 to 3 carbon atoms) or a carbonyl group. The alkylene group may have a substituent, and the substituent T described below is preferable.

・ X
X represents an electron withdrawing group. An electron-withdrawing group is a substituent having an electron-withdrawing property due to an electronic effect. If the substituent constant σ _p of the Hammett rule, which is a measure of the electron-withdrawing property and electron-donating property of a substituent, is used. , Σ _p value is a substituent of 0 or more. Hammett's rule was established in 1935 by L.L. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include σ _p value and σ _m value, and these values can be found in many general books. A. Dean ed., “Lange's Handbook of Chemistry”, 12th edition, 1979 (Mc Graw-Hill) and “Areas of Chemistry”, No. 122, 96-103, 1979 (Nankodo), Corwin Hansch, A . LEO and R.M. W. TAFT “A Survey of Hammett Substitute Students and Resonance and Field Parameters” Chem. Rev. 1991, 91, 165-195. In the present embodiment, each substituent is limited or explained by Hammett's substituent constant σ _p, but this is limited only to a substituent having a known value that can be found in the above-mentioned book. Needless to say, it also includes a substituent that would be included in the range when the value was unknown based on the Hammett rule even if the value was unknown.

Preferably 0.1 to 1.0 substituent constant sigma _p value, and more preferably 0.2-1.0, most preferably 0.3 to 1.0.

Specific examples of the substituent for X include a cyano group (—CN), an alkoxycarbonyl group (—COOR ¹⁶ ), and a carbamoyl group (—CON (R ¹⁸ ) ₂ ).
R ¹⁶ represents a C 1-6 alkyl group that may intervene with a carbonyl group (—CO—), an ether group (—O—), or an imino group (—NR ¹⁷ —). R ¹⁶ is preferably an alkyl group having no hetero atom, more preferably a methyl group, an ethyl group, an i-propyl group, or a t-butyl group. R ¹⁶ may have a substituent, and examples of the substituent include the substituent T described below.
R ¹⁷ represents a hydrogen atom or an alkyl group. When R ¹⁷ is an alkyl group, it preferably has 1 to 4 carbon atoms, more preferably a methyl group, an ethyl group, an i-propyl group, or a t-butyl group. R ¹⁷ may have a substituent, and examples of the substituent include the substituent T described later.
R ¹⁸ represents a group having the same meaning as R ¹⁷ .
X is preferably a cyano group (—CN) or an alkoxycarbonyl group (—COOR ¹⁶ ), and more preferably a cyano group (—CN).

Hereinafter, σp values are shown for some of the exemplified substituents.

The function of each substituent or linking group is not definitive, but is estimated as follows. The linking group L ^11, alkylene group, by a carbonyl group, work potential adjustment action is considered to be able to effectively coat formed in the range of operating potential in the secondary battery. Among these, if L ¹¹ is a carbonyl group, it is considered that the electron withdrawing property further acts to improve the film forming property. Further, it is presumed that the terminal substituent of R ¹⁵ contributes to the stabilization of lithium ions in the formed film.

Specific examples of the compound represented by the formula (I-1) are shown below, but the present embodiment is not construed as being limited thereby.

Me: methyl group tBu: t-butyl group

The compound represented by the above formula (I-1) can be synthesized by a conventional method. Specifically, the procedures of the synthesis examples described later can be referred to.

The content of the specific cyclopropane compound represented by the formula (I-1) is not particularly limited, but is 0.005 to 20% by mass with respect to the total mass of the electrolytic solution, and 0.01% by mass or more. It is more preferable that the content is 0.05% by mass or more. By setting it as more than said lower limit, the effect of this embodiment fully expresses and decomposition | disassembly of electrolyte solution can be suppressed and it is preferable. The upper limit is more preferably 15% by mass or less, and particularly preferably 10% by mass or less. By setting it to the upper limit value or less, it is preferable because excessive addition can be avoided and adverse effects on battery performance can be prevented.
The specific cyclopropane compound represented by the formula (I-1) may be used alone or in combination.

<Embodiment II>
In the nonaqueous electrolytic solution of the present embodiment, a specific cyclopropane compound is contained in the electrolytic solution. Thereby, when it applies to a secondary battery, various performance can be improved and also the load characteristic in a positive electrode can be improved. The reason for this is not clear, but is estimated as follows. The cyclopropane compound having a spiro ring structure used in this embodiment has a carbonyl group next to the cyclopropyl group (α position). It is considered that the carbonyl group has the property of attracting electrons, and its action facilitates the appropriate opening of the cyclopropane ring and promotes the formation of an ideal polymer at or near the electrode surface. Furthermore, it is presumed that the above-mentioned cyclic structure containing a carbonyl group also works favorably and improves not only the negative electrode but also the positive electrode characteristics. That is, the cyclopropane ring of a specific cyclopropane compound having a spiro ring structure is opened, a polymer having a more desirable form for the positive electrode and the negative electrode is formed to form SEI (Solid Electrolyte Interface), and the above performance in the secondary battery It is thought that it led to improvement.

[Compound represented by Formula (II-1)]
The electrolyte solution for a non-aqueous secondary battery of this embodiment contains a specific cyclopropane compound represented by the following formula (II-1).

・ R ²¹ to R ²⁴
In the formula, R ²¹ to R ²⁴ each represents a hydrogen atom or a substituent, and preferably each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. Specific examples of the alkyl group, aryl group, and alkoxy group include the examples of the substituent T described below. R ²¹ to R ²⁴ may be bonded to each other or condensed to form a ring structure. R ²¹ to R ²⁴ may further have a substituent, and examples of the substituent include the substituent T described later.
Among these, R ²¹ to R ²⁴ are preferably a hydrogen atom, an alkyl group, a fluorine atom, a carbonyl group-containing group, or a cyano group, and particularly preferably a hydrogen atom or an alkyl group.
Examples of the alkyl group include the substituent T described later, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 7 carbon atoms, a methyl group, an ethyl group, an isopropyl group, A tertiary butyl group or a benzyl group is particularly preferred.
As the aryl group, an aryl group having 6 to 26 carbon atoms is preferable, and a phenyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 6 carbon atoms, a methoxy group, an ethoxy group, A propoxy group or a tertiary butoxy group is particularly preferred.
As the carbonyl group-containing group, an alkylcarbonyl group, an amide group, or an alkoxycarbonyl group is preferable, and a methylcarbonyl group, an ethylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, or a tertiary butoxycarbonyl group is particularly preferable. preferable.

・ L ²¹
L ²¹ represents an atomic group forming a ring structure together with the carbon atom of the cyclopropyl group and the carbonyl group. The ring formed by L ²¹ may be any of an aromatic hydrocarbon ring, an aliphatic hydrocarbon ring, an aromatic heterocyclic ring, and an aliphatic heterocyclic ring, but preferably a heterocyclic ring (aromatic heterocyclic ring and aliphatic heterocyclic ring). An aliphatic heterocyclic ring is more preferable. Although the hetero atom which comprises a heterocyclic ring is not specifically limited, An oxygen atom, a nitrogen atom, and a sulfur atom are mentioned, It is preferable that it is an oxygen atom or a nitrogen atom. The ring formed by L ²¹ may have a substituent, and examples of the substituent include a substituent T described later. Note that the aliphatic hydrocarbon ring and the aliphatic heterocyclic ring may contain an unsaturated bond.

In L ²¹ , the ring formed together with the carbon atom of the cyclopropyl group and the carbonyl group (C═O) in the formula preferably contains —CONR ²⁵ — or —COO—. Here, R ²⁵ represents an alkyl group (preferably having 1 to 5 carbon atoms) or an aryl group (preferably having 6 to 24 carbon atoms). Specific examples of the alkyl group or aryl group herein include the examples of the substituent T described later. R ²⁵ may further have a substituent, and examples of the substituent include examples of the substituent T described later.

The compound represented by the formula (II-1) is preferably a compound represented by the following formula (II-2).

・ R ²¹ to R ²⁴
R ²¹ to R ²⁴ have the same meaning as in formula (II-1).

・ L ²²
In the formula, L ²² represents an atomic group that forms a ring structure with the carbon atoms of the two carbonyl groups and the cyclopropyl group in the formula. A preferable range of the ring formed by L ²² is the same as L ²¹ , and any of an aromatic hydrocarbon ring, an aliphatic hydrocarbon ring, an aromatic heterocyclic ring, and an aliphatic heterocyclic ring may be used. Ring and aliphatic heterocycle) are preferred, and aliphatic heterocycles are more preferred. Although the hetero atom which comprises a heterocyclic ring is not specifically limited, An oxygen atom, a nitrogen atom, and a sulfur atom are mentioned, It is preferable that it is an oxygen atom or a nitrogen atom. The ring formed by L ²¹ may have a substituent, and examples of the substituent include a substituent T described later. Note that the aliphatic hydrocarbon ring and the aliphatic heterocyclic ring may contain an unsaturated bond.

The ring formed by L ²¹ or L ²² is preferably a 5-membered ring or a 6-membered ring, and particularly preferably a 6-membered ring. The ring formed by L ²¹ or L ²² is preferably the following formula (IIa) or (IIb).

* Represents the position of the carbon atom relative to the cyclopropyl stem. X ¹ and X ³ each represents an oxygen atom, CR ²⁵ ₂ or NR ²⁵ . R ²⁵ has the same meaning as described above. X ² is CR ²⁵ ₂ , CS or CO. Y ¹ and Y ² are an oxygen atom, NR ²⁵ , or CR ²⁵ ₂ .

Specific examples of the compound represented by the formula (II-1) are shown below, but the present embodiment is not construed as being limited thereby.

The compound represented by the above formula (II-1) can be synthesized by a conventional method. Specifically, the procedures of the synthesis examples described later can be referred to.

The content of the specific cyclopropane compound represented by the formula (II-1) is not particularly limited, but is 0.005 to 20% by mass and 0.01% by mass or more with respect to the total mass of the electrolytic solution. It is more preferable that the content is 0.05% by mass or more. By setting it as more than said lower limit, the effect of this embodiment fully expresses and decomposition | disassembly of electrolyte solution can be suppressed and it is preferable. The upper limit is more preferably 15% by mass or less, and particularly preferably 10% by mass or less. By setting it to the upper limit value or less, it is preferable because excessive addition can be avoided and adverse effects on battery performance can be prevented.
The specific cyclopropane compound represented by the formula (II-1) may be used alone or in combination of two or more.

<Embodiment III>
In the nonaqueous electrolytic solution of the present embodiment, a specific cyclopropane compound is contained in the electrolytic solution. Thereby, when it applies to a secondary battery, various performance can be improved and also the load characteristic in a positive electrode can be improved. The reason for this is not clear, but is estimated as follows. The compound having a vinyl group disclosed in Patent Document 1 forms a film on the negative electrode, thereby improving the stability at high temperatures. However, the resistance due to the negative electrode coating increases, which may cause a reduction in load characteristics and cycle characteristics. On the other hand, in the present embodiment, it is presumed that the specific cyclopropane compound having no vinyl group as described above acts favorably and improves not only the negative electrode but also the positive electrode characteristics. That is, the cyclopropane ring of the specific cyclopropane compound is opened, and a polymer having a desirable form for the positive electrode and the negative electrode is formed to form SEI (Solid Electrolyte Interface), which has led to the improvement of the above-mentioned various performances in the secondary battery. It is done.

[Compound represented by Formula (III-1)]
The electrolyte solution for a non-aqueous secondary battery of this embodiment contains a specific cyclopropane compound represented by the following formula (III-1).

・ R ³¹ to R ³⁴
In the formula, each of R ³¹ to R ³⁴ independently represents a hydrogen atom or a substituent, and preferably represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. Specific examples of the alkyl group, aryl group, and alkoxy group include the examples of the substituent T described below. R ³¹ to R ³⁴ may be bonded to each other or condensed to form a ring structure. R ³¹ to R ³⁴ may further have a substituent, and examples of the substituent include the substituent T described later.
R ³¹ to R ³⁴ are each independently preferably a hydrogen atom, an alkyl group, a fluorine atom, a carbonyl group-containing group, or a cyano group, and particularly preferably a hydrogen atom, an alkyl group, a carbonyl group-containing group, or a cyano group.
Examples of the alkyl group include the substituent T described later, preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 7 carbon atoms, a methyl group, an ethyl group, an isopropyl group, A tertiary butyl group or a benzyl group is particularly preferred.
As the aryl group, an aryl group having 6 to 26 carbon atoms is preferable, and a phenyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 6 carbon atoms, a methoxy group, an ethoxy group, A propoxy group or a tertiary butoxy group is particularly preferred.
As the carbonyl group-containing group, an alkylcarbonyl group, an amide group, or an alkoxycarbonyl group is preferable, and a methylcarbonyl group, an ethylcarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, or a tertiary butoxycarbonyl group is particularly preferable. preferable.

・ L ³¹
L ³¹ represents an oxygen atom, —NR ³⁵ —, or a carbonyl group. Preferably, it is an oxygen atom or a carbonyl group. R ³⁵ has the same meaning as defined in L ³² described later. When expressed as (L ³¹ ) n in the formula, the linking group formed by this is preferably a carbonyloxy group, an amide group, or —COR ³⁶ — (R ³⁶ represents an alkylene group having 1 to 3 carbon atoms). R ³⁶ may further have a substituent, and examples of the substituent include the substituent T described later.

・ L ³²
L ³² represents an alkylene group (preferably having 1 to 4 carbon atoms), O, S, SO ₂ , or —NR ³⁵ —, and R ³⁵ is an alkyl group (preferably having 1 to 5 carbon atoms) or an aryl group (preferably Represents a carbon number of 6 to 24). Specific examples of the alkyl group or aryl group herein include the examples of the substituent T described later. The R ³⁵ may further have a substituent, and examples of the substituent include the substituent T described later. The substituents of L ³¹ to L ³² may be bonded to each other or condensed to form a ring structure. When there are a plurality of L ³¹ and L ³² , they may be different from each other.

・ N, m
n and m each independently represent 1 or 2. n + m is preferably 3 or 4, and more preferably 3. Note that a structure formed by-(L ³¹ ) n- (L ³² ) m- in the formula is never -CO-O-CO-. When n and m are 2, the plurality of structural parts defined there may be different from each other.

[Compound represented by Formula (III-2)]
The compound represented by the formula (III-1) is preferably a compound represented by the following formula (III-2) or (III-3).

In the above formula, R ³¹ to R ³⁴ and L ³² have the same ^meaning as in formula (III-1).

Specific examples of the compound represented by the formula (III-1) are shown below, but the present embodiment is not construed as being limited thereby.

Me: methyl group Et: ethyl group

The compound represented by the above formula (III-1) can be synthesized by a conventional method. Specifically, the procedures of the synthesis examples described later can be referred to.

The content of the specific cyclopropane compound represented by the formula (III-1) is not particularly limited, but is 0.005 to 20% by mass with respect to the total mass of the electrolytic solution, and 0.01% by mass or more. It is more preferable that the content is 0.05% by mass or more. By setting it as more than said lower limit, the effect of this embodiment fully expresses and decomposition | disassembly of electrolyte solution can be suppressed and it is preferable. The upper limit is more preferably 15% by mass or less, and particularly preferably 10% by mass or less. By setting it to the upper limit value or less, it is preferable because excessive addition can be avoided and adverse effects on battery performance can be prevented.
The specific cyclopropane compound represented by the formula (III-1) may be used alone or in combination of two or more.

In addition, in this specification, it uses for the meaning containing the salt and its ion other than the said compound itself about the display of a compound. Moreover, it is the meaning including the derivative | guide_body which changed the predetermined part in the range with the desired effect. In addition, in the present specification, a substituent that does not specify substitution / non-substitution (the same applies to a linking group) means that the group may have an arbitrary substituent. This is also synonymous for compounds that do not specify substitution / non-substitution. Preferred substituents include the following substituent T. When a plurality of substituents and ligands are close to each other, they may be connected to each other or condensed to form a ring without particular notice.

Examples of the substituent T include the following.
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl A group (preferably an alkenyl group having 2 to 20 carbon atoms such as vinyl, allyl, oleyl and the like), an alkynyl group (preferably an alkynyl group having 2 to 20 carbon atoms such as ethynyl, butadiynyl, phenylethynyl and the like), A cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), an aryl group (preferably an aryl group having 6 to 26 carbon atoms, for example, Phenyl, 1-naphthyl, 4-methoxyphenyl, -Chlorophenyl, 3-methylphenyl, etc.), heterocyclic groups (preferably heterocyclic groups having 2 to 20 carbon atoms, such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2 -Oxazolyl etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, benzyloxy etc.), an aryloxy group (preferably an aryloxy group having 6 to 26 carbon atoms) For example, phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), alkoxycarbonyl groups (preferably alkoxycarbonyl groups having 2 to 20 carbon atoms, such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc.) ), Amino group (preferably carbon Amino groups having 0 to 20 atoms, such as amino, N, N-dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc., sulfonamido groups (preferably sulfonamido having 0 to 20 carbon atoms) A group such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc., an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms such as acetyloxy, benzoyloxy, etc.), a carbamoyl group (preferably A carbamoyl group having 1 to 20 carbon atoms, such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), an acylamino group (preferably an acylamino group having 1 to 20 carbon atoms, such as acetylamino, benzoylamino, etc.) , Cyano group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, An iodine atom, etc.), more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an amino group, an acylamino group, a cyano group or a halogen atom, particularly preferably Is an alkyl group, an alkenyl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group, or a cyano group.

When a compound or a substituent includes an alkyl group, an alkenyl group, etc., these may be linear or branched, and may be substituted or unsubstituted. When an aryl group, a heterocyclic group, or the like is included, they may be monocyclic or condensed, and may be substituted or unsubstituted.

[Organic solvent]
The organic solvent used in the present invention is preferably a cyclic carbonate, a chain carbonate, or a cyclic ester. For example, ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, γ- Butyrolactone, γ-valerolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1,4- Dioxane, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, ethyl trimethyl acetate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methyl Toxipropionitrile, N, N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N, N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethyl sulfoxide or dimethyl sulfoxide phosphate It is done. These may be used alone or in combination of two or more. Among them, at least one member selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate is preferable. Particularly, a high viscosity (high dielectric constant) solvent such as ethylene carbonate or propylene carbonate (for example, ratio A combination of a dielectric constant ε ≧ 30) and a low viscosity solvent such as dimethyl carbonate, ethyl methyl carbonate, or diethyl carbonate (for example, viscosity ≦ 1 mPa · s) is more preferable. This is because the dissociation property of the electrolyte salt and the ion mobility are improved.

Further, the solvent may contain a cyclic carbonate having an unsaturated bond. This is because the chemical stability of the electrolytic solution is further improved. Examples of the cyclic carbonate having an unsaturated bond include at least one selected from the group consisting of vinylene carbonate compounds, vinyl ethylene carbonate compounds, and methylene ethylene carbonate compounds.

Examples of vinylene carbonate compounds include vinylene carbonate (1,3-dioxol-2-one), methyl vinylene carbonate (4-methyl-1,3-dioxol-2-one), and ethyl vinylene carbonate (4-ethyl- 1,3-dioxol-2-one), 4,5-dimethyl-1,3-dioxol-2-one, 4,5-diethyl-1,3-dioxol-2-one, 4-fluoro-1,3 And -dioxol-2-one and 4-trifluoromethyl-1,3-dioxol-2-one.

Examples of the vinyl ethylene carbonate compound include vinyl ethylene carbonate (4-vinyl-1,3-dioxolan-2-one), 4-methyl-4-vinyl-1,3-dioxolan-2-one, and 4-ethyl. -4-vinyl-1,3-dioxolane-2-one, 4-n-propyl-4-vinyl-1,3-dioxolan-2-one, 5-methyl-4-vinyl-1,3-dioxolane-2 -One, 4,4-divinyl-1,3-dioxolan-2-one, 4,5-divinyl-1,3-dioxolan-2-one and the like.

Examples of the methylene ethylene carbonate compound include 4-methylene-1,3-dioxolan-2-one, 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one, and 4,4-diethyl-5-one. And methylene-1,3-dioxolan-2-one.

These may be used alone, or a plurality of types may be mixed and used. Among these, vinylene carbonate is preferable. This is because a high effect can be obtained.

[Electrolytes]
The electrolyte is preferably a metal ion belonging to Group 1 or Group 2 of the periodic table or a salt thereof, and is appropriately selected depending on the intended use of the electrolytic solution. For example, lithium salt, potassium salt, sodium salt, calcium salt, magnesium salt and the like can be mentioned. When used in a secondary battery or the like, lithium salt is preferable from the viewpoint of output. When the electrolytic solution is used as an electrolyte of a non-aqueous electrolytic solution for a lithium secondary battery, a lithium salt may be selected as a metal ion salt. The lithium salt is not particularly limited as long as it is a lithium salt usually used for an electrolyte of a non-aqueous electrolyte solution for a lithium secondary battery. For example, those described below are preferable.

(L-1) Inorganic lithium salts: inorganic fluoride salts such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ ; perhalogenates such as LiClO ₄ , LiBRO ₄ , LiIO ₄ ; inorganic chloride salts such as LiAlCl ₄ etc.

(L-2) Fluorine-containing organic lithium salt: perfluoroalkane sulfonate such as LiCF ₃ SO ₃ ; LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , Perfluoroalkanesulfonylimide salts such as LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ); perfluoroalkanesulfonylmethide salts such as LiC (CF ₃ SO ₂ ) ₃ ; Li [PF ₅ (CF ₂ CF ₂ CF ₃ )], Li [PF ₄ (CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₃ ) ₃ ], Li [PF ₅ (CF ₂ CF ₂ CF ₂ CF _{3 )], Li [PF 4 (} CF 2 CF 2 CF 2 CF 3) 2], Li [PF 3 (CF 2 CF 2 CF 2 CF 3) 3] fluoroalkyl fluoride such as potash Acid salts, and the like.

(L-3) Oxalatoborate salt: lithium bis (oxalato) borate, lithium difluorooxalatoborate and the like.

Among these, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiClO ₄ , Li (Rf ¹ SO ₃ ), LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ) ₂ Lithium bis (oxalato) borate salts are preferred, LiPF ₆ , LiBF ₄ , LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) ( More preferred are lithium imide salts such as Rf ² SO ₂ ) ₂ and lithium bis (oxalato) borate salts. Here, Rf ^{1 and} Rf ² each represent a perfluoroalkyl group.
In addition, the lithium salt used for electrolyte solution may be used individually by 1 type, or may combine 2 or more types arbitrarily.
The electrolyte content is added in such an amount that a preferable salt concentration described below in the method for preparing the electrolytic solution is obtained. The concentration is appropriately selected according to the purpose of use of the electrolytic solution, but is generally 10% by mass to 50% by mass, more preferably 15% by mass to 30% by mass, based on the total mass of the electrolytic solution. In addition, when evaluating as an ion density | concentration, what is necessary is just to calculate by salt conversion with the metal applied suitably.

[Method for preparing electrolytic solution]
Next, a typical method for adjusting the electrolytic solution of the present invention will be described by taking as an example a case where a lithium salt is used as a metal ion salt. The electrolytic solution of the present embodiment is prepared by dissolving a lithium salt and various additives that are optionally added in the nonaqueous electrolytic solution solvent.

In the present invention, “non-water” means substantially not containing water, and may contain a small amount of water as long as the effect of the invention is not hindered. In view of obtaining good characteristics, the water content is preferably 200 ppm or less, and more preferably 100 ppm or less. Although there is no particular lower limit, it is practical that it is 10 ppm or more considering inevitable mixing.

(Composition of electrolyte)
The metal salt concentration in the prepared electrolytic solution has an appropriate concentration range for exhibiting high ionic conductivity because the viscosity of the electrolytic solution increases as the concentration increases. A preferred concentration range is 10% by mass to 50% by mass, and more preferably 15% by mass to 30% by mass, based on the total mass of the electrolytic solution. The viscosity of the electrolytic solution is not particularly limited, but is preferably 5 to 0.5 mPa · s, and more preferably 5 to 0.1 mPa · s.

(kit)
The electrolytic solution of the present invention may be a kit composed of a plurality of liquids or powders. For example, the first agent (first liquid) is composed of an electrolyte and an organic solvent, the second agent (second liquid) is composed of the specific cyclopropane compound and an organic solvent, and the two liquids are mixed before use. It may be in the form of liquid preparation. The content of each component at this time is preferably in the above range after mixing.

[Secondary battery]
An embodiment of a secondary battery according to the present invention will be described with reference to FIG. The lithium ion secondary battery 10 of the present embodiment includes an electrolyte solution 5 for a non-aqueous secondary battery, a positive electrode C (positive electrode current collector 1, positive electrode active material layer 2) capable of inserting and releasing lithium ions, and lithium ions. Negative electrode A (negative electrode current collector 3, negative electrode active material layer 4). In addition to these essential members, considering the purpose of use of the battery, the shape of the potential, etc., a separator 9 disposed between the positive electrode and the negative electrode, a current collecting terminal (not shown), an outer case, etc. (Not shown). If necessary, a protective element may be attached to at least one of the inside of the battery and the outside of the battery. By adopting such a structure, lithium ion exchanges a and b are generated in the electrolytic solution 5, and charging / discharging α / β can be performed. Electric power can be stored. Hereinafter, the configuration of a lithium secondary battery which is a preferred embodiment of the present invention will be described in detail.

(Battery shape)
The battery shape to which the lithium secondary battery of the present embodiment is applied is not particularly limited, and examples thereof include a bottomed cylindrical shape, a bottomed square shape, a thin shape, a sheet shape, and a paper shape. Any of these may be used. Further, it may be of a different shape such as a horseshoe shape or a comb shape considering the shape of the system or device to be incorporated. Among them, from the viewpoint of efficiently releasing the heat inside the battery to the outside, a square shape such as a bottomed square shape or a thin shape having at least one relatively flat and large surface is preferable.

In the case of a battery having a bottomed cylindrical shape, since the outer surface area with respect to the power generating element to be filled becomes small, it is preferable to design so that Joule heat generated by the internal resistance at the time of charging or discharging efficiently escapes to the outside. Moreover, it is preferable to design so that the filling ratio of the substance having high thermal conductivity is increased and the temperature distribution inside is reduced. FIG. 2 shows an example of a bottomed cylindrical lithium secondary battery 100. This battery is a bottomed cylindrical lithium secondary battery 100 in which a positive electrode sheet 14 and a negative electrode sheet 16 stacked with a separator 12 interposed therebetween are wound and stored in an outer can 18. In addition, in the figure, 20 is an insulating plate, 22 is a sealing plate, 24 is a positive current collector, 26 is a gasket, 28 is a pressure sensitive valve element, and 30 is a current interrupting element. In addition, although the illustration in the enlarged circle has changed hatching in consideration of visibility, each member corresponds to the whole drawing by reference numerals.

(Members constituting the battery)
Next, each member of the lithium secondary battery of this embodiment will be described. The lithium secondary battery of the present invention includes at least the electrolyte solution for a non-aqueous battery of the present invention as an electrolytic solution.
(Electrolyte)
The electrolytic solution used in the lithium secondary battery of this embodiment preferably contains an organic solvent, the specific cyclopropane compound described above, and an electrolyte salt (electrolytic solution 5 (FIG. 1)). The electrolyte salt used in the electrolyte for a non-aqueous secondary battery is a salt of a metal ion belonging to Group 1 or Group 2 of the aforementioned periodic table, and the embodiment of the electrolyte for a non-aqueous secondary battery Those described in detail in (1) can be used. Similarly, the organic solvent (nonaqueous electrolyte solvent) used in the lithium secondary battery can be the same as described in the embodiment of the electrolyte for nonaqueous secondary battery. Furthermore, other additives can be added to further improve the performance.

In order to improve the performance of the battery, various additives can be used in the electrolytic solution depending on the purpose as long as the effects of the present invention are not impaired. As such an additive, such a functional additive such as an overcharge inhibitor, a negative electrode film forming agent, and a positive electrode protective agent may be used.

Also, the combined use of a negative electrode film forming agent and a positive electrode protective agent, and the combined use of an overcharge inhibitor, a negative electrode film forming agent, and a positive electrode protective agent are particularly preferable.

The content ratio of these functional additives in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass or more, particularly preferably 0.1% by mass or more, respectively, with respect to the entire non-aqueous electrolyte solution. More preferably, it is 0.2% by mass or more, and the upper limit is preferably 5% by mass or less, particularly preferably 3% by mass or less, and further preferably 2% by mass or less. By adding these compounds, it is possible to suppress rupture / ignition of the battery at the time of abnormality due to overcharge, and to improve the capacity maintenance characteristic and cycle characteristic after high-temperature storage.

(Electrode mixture)
An electrode mixture is a composite in which a dispersion such as an active material and a conductive agent, a binder, and a filler is applied on a current collector (electrode substrate). In a lithium battery, the active material is a positive electrode active material. It is preferable to use a negative electrode mixture in which a certain positive electrode mixture and an active material are negative electrode active materials. Next, the positive electrode active material, the negative electrode active material, the conductive agent, the binder, the filler, and the current collector that constitute the electrode mixture will be described.

(Positive electrode active material)
As the positive electrode active material, a transition metal oxide capable of reversibly inserting and releasing lithium ions can be used, but a lithium-containing transition metal oxide is preferably used. Preferred examples of the lithium-containing transition metal oxide preferably used as the positive electrode active material include oxides containing lithium-containing Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, and W. Alkali metals other than lithium (elements of Group 1 (Ia) and Group 2 (IIa) of the periodic table) and / or Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P , B, etc. may be mixed. The mixing amount is preferably 0 to 30 mol% with respect to the transition metal.

Among the lithium-containing transition metal oxides preferably used as the positive electrode active material, a lithium compound / transition metal compound (wherein the transition metal is selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo, W) And a mixture synthesized so that the total molar ratio is 0.3 to 2.2 is more preferable.

Further, among the lithium compounds / transition metal compounds, Li _g M3O ₂ (M3 represents one or more elements selected from Co, Ni, Fe, and Mn. _G represents 0 to 1.2. ) Or a material having a spinel structure represented by Li _h M4 ₂ O (M4 represents Mn, h represents 0 to 2). As M3 and M4, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P, and B may be mixed in addition to the transition metal. The mixing amount is preferably 0 to 30 mol% with respect to the transition metal.

The _Li g M3O material containing _2, among the materials having the spinel structure represented by _{Li h M4 2 O, Li g} CoO 2, Li g NiO 2, Li g MnO 2, Li g Co j Ni 1-j O _{2, Li h Mn 2 O 4} , LiNi j Mn 1-j O 2, LiCo j Ni h Al 1-j-h O 2, LiCo j Ni h Mn 1-j-h O 2, LiMn h Al 2-h O ₄ , LiMn _h Ni _2-h O ₄ (where g represents 0.02 to 1.2, j represents 0.1 to 0.9, h represents 0 to 2) is particularly preferable. , More preferably _{Li g CoO 2, LiMn 2 O} 4, LiNi 0.85 Co 0.01 Al 0.05 O 2, and is _{LiNi 0.33 Co 0.33 Mn 0.33 O 2} . Of these, an electrode containing Ni is more preferable from the viewpoint of high capacity and high output. Here, the g value and the h value are values before the start of charge / discharge, and are values that increase / decrease due to charge / discharge. In particular,
LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ ,
LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiMn _1.8 Al _0.2 O ₄ ,
LiMn _1.5 Ni _0.5 O ₄ and the like.

As the transition metal of the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu and the like are preferable, and specific examples include, for example, LiFePO ₄ , Li ₃ Fe ₂ (PO ₄ ). ₃ , iron phosphates such as LiFeP ₂ O ₇ , cobalt phosphates such as LiCoPO ₄ , and some of the transition metal atoms that are the main components of these lithium transition metal phosphate compounds are Al, Ti, V, Cr, Mn , Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si and the like substituted with other metals.
Furthermore, a solid solution positive electrode material (for example, Li ₂ MnO ₃ -LiMO ₂ (M: metal such as Ni, Co, Mn)) having a high potential close to 5 V and a very high specific capacity exceeding 250 mAh / g is the next generation lithium. It has attracted much attention as a positive electrode material for ion batteries, and the electrolytic solution of the present invention is preferably combined with these solid solution positive electrode materials.

In the nonaqueous electrolyte secondary battery, the average particle size of the positive electrode active material used is not particularly limited, but is preferably 0.1 μm to 50 μm. The specific surface area is not particularly limited, but is preferably 0.01 m ² / g to 50 m ² / g by the BET method. Further, the pH of the supernatant when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.

A well-known pulverizer or classifier is used to make the positive electrode active substance have a predetermined particle size. For example, a mortar, a ball mill, a vibration ball mill, a vibration mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill, a sieve, or the like is used. The positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

(Negative electrode active material)
The negative electrode active material is not particularly limited as long as it can reversibly insert and release lithium ions. Carbonaceous materials, metal oxides such as tin oxide and silicon oxide, metal composite oxides, simple lithium and lithium Examples thereof include lithium alloys such as aluminum alloys and metals that can form alloys with lithium such as Sn and Si. These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Of these, carbonaceous materials or lithium composite oxides are preferably used from the viewpoint of safety.
In addition, the metal composite oxide is not particularly limited as long as it can occlude and release lithium, but it contains silicon, titanium and / or lithium (for example, lithium titanate) as a constituent component so as to have a high current. It is preferable from the viewpoint of density charge / discharge characteristics.

The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. Examples thereof include carbonaceous materials obtained by baking various synthetic resins such as artificial pitches such as petroleum pitch, natural graphite, and vapor-grown graphite, and PAN-based resins and furfuryl alcohol resins. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA-based carbon fiber, lignin carbon fiber, glassy carbon fiber, activated carbon fiber, mesophase micro Examples thereof include spheres, graphite whiskers, and flat graphite.

These carbonaceous materials can be divided into non-graphitizable carbon materials and graphite-based carbon materials depending on the degree of graphitization. Further, the carbonaceous material preferably has an interplanar spacing, density, and crystallite size described in JP-A-62-222066, JP-A-2-6856, and 3-45473. The carbonaceous material does not have to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, or the like is used. You can also.

The metal oxide and metal composite oxide, which are negative electrode active materials used in lithium secondary batteries, need only contain at least one of them. As the metal oxide and metal complex oxide, amorphous oxide is particularly preferable, and chalcogenite, which is a reaction product of a metal element and an element of Group 16 of the periodic table, is also preferably used. The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays, which has a broad scattering band having a peak in the region of 20 ° to 40 ° in terms of 2θ, and is a crystalline diffraction line. You may have. The strongest intensity of crystalline diffraction lines seen from 2 ° to 40 ° to 70 ° is 100 times the diffraction line intensity at the peak of the broad scattering band seen from 2 ° to 20 °. It is preferable that it is 5 times or less, and it is particularly preferable not to have a crystalline diffraction line.

Among the compound group consisting of the amorphous oxide and the chalcogenide, an amorphous oxide of a semi-metal element and a chalcogenide are more preferable, and elements of Groups 13 (IIIB) to 15 (VB) of the periodic table, Particularly preferred are oxides and chalcogenides composed of one kind of Al, Ga, Si, Sn, Ge, Pb, Sb, Bi or a combination of two or more kinds thereof. Specific examples of preferred amorphous oxides and chalcogenides include metal compounds such as Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , SnSiO ₃ , GeS, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , SnSiS _{3 and the} like are preferable. Moreover, these may be a complex oxide with lithium oxide, for example, Li ₂ SnO ₂ .

In the nonaqueous electrolyte secondary battery, the average particle size of the negative electrode active material used is preferably 0.1 μm to 60 μm. To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill or a sieve is preferably used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle size, classification is preferably performed. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be used both dry and wet.

The chemical formula of the compound obtained by the firing method can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method and a mass difference between powders before and after firing as a simple method.

Examples of the negative electrode active material that can be used in combination with the amorphous oxide negative electrode active material centering on Sn, Si, and Ge include carbon materials that can occlude and release lithium ions or lithium metal, lithium, lithium alloys, lithium A metal that can be alloyed with is preferable.

In the present invention, it is preferable to use lithium titanate, more specifically, lithium-titanium oxide (Li [Li _1/3 Ti _5/3 ] O ₄ ) as the active material of the negative electrode. By using this as the negative electrode active material, the SEI formation effect by the specific cyclopropane compound is further enhanced, and more excellent battery performance can be exhibited.
The electrolyte solution of the present invention is preferably combined with a high potential negative electrode (preferably lithium / titanium oxide, potential 1.55 V) or a combination with a low potential negative electrode (preferably a carbon material, potential 0.1 V). Also exhibits excellent properties. Further, metal or metal oxide negative electrode (preferably Si, Si oxide, Si / silicon oxide, Sn, Sn oxide, SnB _x P _y O _z , Cu, which can be alloyed with lithium, which is being developed for higher capacity) / Sn and a plurality of these composites), and a battery using a composite of these metals or metal oxides and a carbon material as a negative electrode.

(Conductive material)
Any conductive material may be used as long as it is an electron conductive material that does not cause a chemical change in the constructed secondary battery, and any known conductive material can be used. Usually, natural graphite (scale-like graphite, scale-like graphite, earth-like graphite, etc.), artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber and metal powder (copper, nickel, aluminum, silver (Japanese Patent Laid-Open No. Sho 63-63)) 10148,554), etc.), metal fibers or polyphenylene derivatives (described in JP-A-59-20971) can be contained as one kind or a mixture thereof. Among these, the combined use of graphite and acetylene black is particularly preferable. The addition amount of the conductive agent is preferably 1 to 50% by mass, and more preferably 2 to 30% by mass. In the case of carbon or graphite, 2 to 15% by mass is particularly preferable.

(Binder)
Examples of the binder include polysaccharides, thermoplastic resins, and polymers having rubber elasticity. Among them, for example, starch, carboxymethylcellulose, cellulose, diacetylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium alginate, Polyacrylic acid, sodium polyacrylate, polyvinyl phenol, polyvinyl methyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylonitrile, polyacrylamide, polyhydroxy (meth) acrylate, water-soluble polymers such as styrene-maleic acid copolymer, polyvinyl chloride , Polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride Ride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate, and other (meth) acrylic (Meth) acrylic acid ester copolymer containing acid ester, (meth) acrylic acid ester-acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene-butadiene copolymer, acrylonitrile -Butadiene copolymer, polybutadiene, neoprene rubber, fluoro rubber, polyethylene oxide, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane Tan resins, polyester resins, phenolic resins, emulsion (latex) or a suspension such as an epoxy resin is preferable, a latex of polyacrylate, carboxymethyl cellulose, polytetrafluoroethylene, polyvinylidene fluoride is more preferable.

Binders can be used alone or in combination of two or more. When the amount of the binder added is small, the holding power and cohesive force of the electrode mixture are weakened. If the amount is too large, the electrode volume increases and the capacity per electrode unit volume or unit mass decreases. For this reason, the addition amount of the binder is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass.

(Filler)
As the material for forming the filler, any fibrous material that does not cause a chemical change in the secondary battery can be used. Usually, fibrous fillers made of materials such as olefin polymers such as polypropylene and polyethylene, glass, and carbon are used. The amount of filler added is not particularly limited, but is preferably 0 to 30% by mass.

(Current collector)
As the positive / negative current collector, an electron conductor that does not cause a chemical change in a non-aqueous electrolyte secondary battery is used. As the current collector of the positive electrode, in addition to aluminum, stainless steel, nickel, titanium, etc., the surface of aluminum or stainless steel is preferably treated with carbon, nickel, titanium, or silver. Among them, aluminum and aluminum alloys are preferable. More preferred.

The negative electrode current collector is preferably copper, stainless steel, nickel, or titanium, and more preferably copper or a copper alloy.

As the shape of the current collector, a film sheet shape is usually used, but a net, a punched material, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like can also be used. The thickness of the current collector is not particularly limited, but is preferably 1 μm to 500 μm. Moreover, it is also preferable that the current collector surface is roughened by surface treatment.
An electrode mixture of the lithium secondary battery is formed by a member appropriately selected from these materials.

(Separator)
The separator used in the lithium secondary battery is particularly limited as long as it is a material that mechanically insulates the positive electrode and the negative electrode, has ion permeability, and has oxidation / reduction resistance at the contact surface between the positive electrode and the negative electrode. There is no. As such a material, a porous polymer material, an inorganic material, an organic-inorganic hybrid material, glass fiber, or the like is used. These separators preferably have a shutdown function for ensuring safety, that is, a function of closing the gap at 80 ° C. or higher to increase resistance and interrupting current, and the closing temperature is 90 ° C. or higher and 180 ° C. or lower. Preferably there is. From the viewpoint of the strength of the separator, it is particularly preferable to use a separator reinforced with an inorganic material or glass fiber.

The shape of the holes of the separator is usually circular or elliptical, and the size is 0.05 μm to 30 μm, preferably 0.1 μm to 20 μm. Furthermore, it may be a rod-like or irregular-shaped hole as in the case of making by a stretching method or a phase separation method. The ratio of these gaps, that is, the porosity, is 20% to 90%, preferably 35% to 80%.

The polymer material may be a single material such as polyethylene or polypropylene, or two or more composite materials. What laminated | stacked the 2 or more types of microporous film which changed the hole diameter, the porosity, the obstruction | occlusion temperature of a hole, etc. is preferable.

Examples of the inorganic material include oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate, and those having a particle shape or fiber shape are used. . As the form, a thin film shape such as a non-woven fabric, a woven fabric, or a microporous film is used. As the thin film shape, those having a pore diameter of 0.01 μm to 1 μm and a thickness of 5 μm to 50 μm are preferably used. In addition to the independent thin film shape, a separator formed by forming a composite porous layer containing the inorganic particles on the surface layer of the positive electrode and / or the negative electrode using a resin binder can be used. For example, alumina particles having a 90% particle diameter of less than 1 μm are formed on both surfaces of the positive electrode as a porous layer using a fluororesin binder.

[Applications of lithium secondary batteries]
Lithium secondary batteries can be used for various applications because secondary batteries with good cycleability can be manufactured.
Although there is no particular limitation on the application mode, for example, when installed in an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile fax, a mobile phone Copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, minidisc, electric shaver, transceiver, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, etc. It is done. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with a solar cell.

The metal ion used for charge transport in the secondary battery is not particularly limited, but is preferably a metal ion belonging to Group 1 or Group 2 of the periodic table. Among these, it is preferable to use lithium ions, sodium ions, magnesium ions, calcium ions, aluminum ions, and the like. There are many documents and books such as the patent documents listed at the beginning for general technical matters regarding secondary batteries using lithium ions, which are helpful. For other secondary batteries using sodium ions, Journal of Electrochemical Society; Electrochemical Science and Technology, USA, 1980, Vol. 127, pages 2097-2099, and the like can be referred to. For magnesium ions, see Nature 407, p. 724-727 (2000) and the like can be referred to. For calcium ions, see J.H. Electrochem. Soc. , Vol. 138, 3536 (1991), etc. can be referred to. In the present invention, it is preferable to apply to a lithium ion secondary battery because of its widespread use, but the other effects also have a desired effect and should not be construed as being limited thereto.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
<Example I>
1. Synthesis of cyclopropane compounds

(Synthesis Example I-1: Synthesis of cyclopropane (SI-1))
To a solution of 2.22 g of 1-cyano-1-cyclopropanecarboxylic acid, 84 ml of methylene chloride and 12 ml of methanol was added dropwise with 12 ml of a 2M trimethylsilyldiazomethane solution in diethyl ether. After completion of foaming, 1 ml of acetic acid was added. The mixture was extracted with methylene chloride, washed with a saturated aqueous sodium hydrogen carbonate solution, dried over sodium sulfate, and concentrated. The obtained organic substance was purified by distillation to obtain 1.9 g of cyclopropane compound (SI-1).

(Synthesis Example I-2: Synthesis of cyclopropane (SI-2))
Glycerol carbonate (5.31 g), dicyclohexylcarbodiimide (9.28 g) and 4-dimethylaminopyridine (55 mg) were dissolved in methylene chloride (60 ml). A solution prepared by dissolving 5 g of 1-cyano-1-cyclopropanecarboxylic acid in 50 ml of methylene chloride was added dropwise at 0 ° C. and reacted at room temperature for 3 hours. The solid was removed by Celite filtration, and then extracted with methylene chloride, washed with saturated brine, dried over sodium sulfate, and concentrated. The obtained organic substance was purified by silica gel chromatography to obtain 6.5 g of cyclopropane compound (SI-2).

(Synthesis Example I-3: Synthesis of cyclopropane (SI-5))
Cyclopropane (SI-5) was obtained in the same manner as in Synthesis Example I-2 using methoxyethoxyethanol as a raw material.

(Synthesis Example I-4: Synthesis of cyclopropane (SI-8))
7.6 g of NaBH ₄ was added to 50 ml of ethanol, and a solution of 23.1 g of methyl 4-bromo-2-cyano-4-methyl-2-pentenoate in 10 ml of ethanol was added dropwise at room temperature. After reacting for 4 hours, 100 ml of distilled water was added, extracted with methylene chloride, concentrated, and purified by distillation under reduced pressure to obtain 7.2 g of cyclopropane compound (SI-8).

(Synthesis Example I-5: Synthesis of cyclopropane (SI-11))
20 ml of dehydrated THF was added to 6 ml of 2M LDA in THF and cooled to -78 ° C. Cyclopropanecarboxylic acid tertiary butyl ester (1.5 ml) was added dropwise, and the mixture was stirred at -78 ° C. for 3 hours. After adding 2.9 ml of 1-bromo-2- (2-methoxyethoxy) ethane and reacting at -78 ° C. for 2 hours, the mixture was stirred at room temperature for 1 hour. A saturated aqueous ammonium chloride solution was added dropwise, the mixture was extracted with ethyl acetate, washed with saturated brine, dried and concentrated. The obtained organic substance was purified by distillation to obtain 0.82 g of a cyclopropane compound (SI-11).

(Synthesis Example I-6: Synthesis of cyclopropane (SI-12))
The cyclopropane compound (SI-11) was dissolved in 25 ml of methylene chloride, 25 ml of trifluoroacetic acid and 0.5 ml of triethylhydrosilane were added at 0 ° C. and reacted at room temperature for 4 hours. 1M aqueous sodium hydroxide solution is added to make alkaline, extracted with ethyl acetate, washed with saturated brine, acidified with 1M aqueous hydrochloric acid solution, extracted with ethyl acetate, washed with saturated brine, organic layer Was dried and concentrated. The obtained cyclopropanecarboxylic acid derivative was esterified in the same manner as in Synthesis Example I-1 to obtain a cyclopropane compound (SI-12).

(Synthesis Example I-7: Synthesis of cyclopropane (SI-13))
Using 1-cyano-1-cyclopropanecarboxylic acid as a raw material, cyclopropane (SI-13) was obtained in the same manner as in Synthesis Example I-5.

(Synthesis Example I-8: Synthesis of cyclopropane (SI-14))
Cyclopropane (SI-14) was obtained in the same manner as in Synthesis Example I-5 using benzyl bromide as a raw material.

(Synthesis Example I-9: Synthesis of cyclopropane (SI-15))
Cyclopropane (SI-15) was obtained in the same manner as in Synthesis Example I-6 using cyclopropane (SI-14) as a raw material.

<Example>
2. Preparation of Electrolyte To 1M LiPF ₆ ethylene carbonate (EC) / ethyl methyl carbonate (EMC) in a volume ratio of 1 to 2, and a volume ratio of 1 to 3 in an electrolyte, the cyclopropane obtained in Synthesis Example I-1 Compound (SI-1) was added in an amount of 0.05% by mass, and test no. An electrolyte solution of I-101 was prepared. The electrolyte solution was prepared in the same manner by changing the type and amount of cyclopropane compound used as shown in the table (Test Nos. I-102 to I-113).

<Comparative example>
An electrolyte solution of 1M LiPF ₆ in ethylene carbonate / ethyl methyl carbonate was used as a comparative example.
Similarly, a comparative example was prepared by adding vinylene carbonate (VC), the following (RI-1), the following (RI-2), and the following (RI-3) in the addition amounts shown in the table.

[Lithium secondary battery]

Lithium cobaltate mixture sheet (electrode capacity 1.5 mAh / cm ² : aluminum foil base, 13 mmφ) on the positive electrode, natural spherical graphite electrode sheet (electrode capacity 1.6 mAh / cm2: Cu foil base, 14.5 mmφ) on the negative electrode, Using a PP porous film (thickness 25 μm, 16 mmφ) as a separator, a lithium secondary battery for evaluation using an electrolytic solution shown in Table 1-1 below was produced.

<Evaluation of cycle performance (discharge capacity retention rate)>
Using a 2032 type battery produced by the above method, in a thermostatic chamber at 30 ° C., after charging at a constant current of 0.7 C until the battery voltage becomes 4.2 V, the current value is set to 0.06 mA at a constant voltage of 4.2 V. Or charging for 2 hours, and then 0.5C constant current discharge was performed until the battery voltage reached 2.75 V, resulting in one cycle. This was repeated until 300 cycles were reached.

<Low-temperature discharge rate evaluation (low-temperature discharge rate)>
Using the 2032 type battery produced by the above method, the discharge capacity ratio at −20 ° C. with respect to 30 ° C. was measured. In a constant temperature bath at 30 ° C, charge at a constant current of 0.1C until the battery voltage reaches 4.2V, then at 4.2V constant voltage, the current value becomes 0.06mA, or charge for 2 hours, then- In a constant temperature bath at 20 ° C., 0.1 C constant current discharge was performed until the 0 battery voltage became 2.75 V, and the discharge capacity was measured.

<Self-discharge characteristic evaluation (capacity remaining rate)>
Using the 2032 type battery produced by the above method, after charging at a constant current of 0.1 C until the battery voltage becomes 4.2 V at 0.4 mA in an environment of 30 ° C., the current value is 4.2 V constant voltage. The battery was charged at 0.06 mA or 2 hours, and 0.1 C constant current discharge was performed until the battery voltage reached 2.75 V, and the initial discharge capacity was measured. Furthermore, after charging at a constant current of 0.1 C until the battery voltage reaches 4.2 V, the current value becomes 0.06 mA at a constant voltage of 4.2 V, or after charging for 2 hours, Left under for 14 days. Then, after taking out to 30 degreeC environment, the discharge capacity when discharging on the same discharge conditions was measured.

<Evaluation of cycleability in Li ₄ Ti ₅ O ₁₂ negative electrode (discharge capacity retention rate)>
The negative electrode was changed to a lithium titanate mixture sheet (electrode capacity 1.6 mAh / cm ² : aluminum foil base, 14.5 mmφ), and the battery voltage was 2. After charging with a constant current of 0.7 C until 8 V, the current value becomes 0.06 mA at a constant voltage of 2.8 V, or charging is performed for 2 hours, and then a constant current of 0.5 C is maintained until the battery voltage reaches 1.8 V. Current discharge was performed to make one cycle. This was repeated until 500 cycles were reached.

<Test results>
1. Discharge capacity maintenance ratio in the _300th cycle (DCMR ₃₀₀ : Discharge Capacity Maintaining Ratio)

(Note 1) Discharge capacity maintenance rate (%) =
(Discharge capacity at the 300th cycle / discharge capacity at the first cycle) × 100

As shown in Table 1-1, the 2032 type non-aqueous electrolyte secondary batteries (test Nos. I-101 to I-114) of the examples are 2032 type non-aqueous electrolyte secondary batteries (test No. It was confirmed that the capacity retention ratio at the 300th cycle was superior to that of .Ic11 to Ic16). As a result, in the negative electrode according to the battery of the example, the cyclopropane compound added to the electrolytic solution receives electrons at the negative electrode, undergoes ring-opening polymerization, and forms a good SEI (Solid Electrolyte Interface) film on the negative electrode surface. This is considered to be due to the suppression of the decomposition of the electrolytic solution.
Further, even when LiMn ₂ O ₄ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ , and LiNi _0.33 Co _0.33 Mn _0.33 O ₂ are used as the positive electrode active material, they are similarly good. The discharge capacity retention rate was shown.

2. Low temperature discharge rate (LTDR: Low Temperature Discharging Rate)

(Note 2) Low temperature discharge rate (%) = (discharge capacity at −20 ° C./discharge capacity at 30 ° C.) × 100

As shown in Table 1-2, the 2032 type non-aqueous electrolyte secondary batteries (test Nos. I-201 to I-208) of the examples are 2032 type non-aqueous electrolyte secondary batteries (test No. .. Ic21 to Ic24) were confirmed to be superior in low-temperature discharge rate. As a result, lithium ions were stabilized in the SEI film formed on the negative electrode surface according to the battery of the example, the lithium ion conductivity in the film (SEI) was improved, and the interface migration resistance was reduced. Presumed to be due.

3. Capacity remaining rate (RCR: Remaining Capacity Ratio)

(Note 3) Capacity remaining rate (%) = (discharge capacity after standing for 14 days / initial discharge capacity) × 100

As shown in Table 1-3, the 2032 type non-aqueous electrolyte secondary batteries (test Nos. I-301 to I-308) of the examples are 2032 type non-aqueous electrolyte secondary batteries (test No. .. I-c31 to I-c34) were confirmed to have better self-discharge characteristics. This result is presumed to be attributable to the fact that the positive electrode was stabilized by the formed coating on the positive electrode surface of the battery of the example, and the self-decomposition of the positive electrode was suppressed.

Discharge capacity maintenance ratio in the 4.500th cycle (DCMR ₅₀₀ : Discharge Capacity Maintaining Ratio)

(Note 4) Discharge capacity maintenance rate (%) =
(Discharge capacity at 500th cycle / discharge capacity at the first cycle) × 100

As shown in Table 1-4, the 2032 type non-aqueous electrolyte secondary batteries (test Nos. I-401 and I-402) of the examples are 2032 type non-aqueous electrolyte secondary batteries (test No. It was confirmed that the capacity retention rate at the 500th cycle was superior to that of. This result shows that the reduction proceeds at a potential higher than the insertion potential of lithium ions as in the case of the graphite negative electrode, a good SEI (Solid Electrolyte Interface) film is formed on the lithium titanate negative electrode, the electrolytic solution is decomposed, and This is considered to be due to suppression of electrode deterioration.
Further, even when LiMn ₂ O ₄ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ , and LiNi _0.33 Co _0.33 Mn _0.33 O ₂ are used as the positive electrode active material, they are similarly good. The discharge capacity retention rate was shown.

<Example II>
1. Synthesis of specific cyclopropane compound (Synthesis Example II-1: Synthesis of spirocyclopropane (SII-1))
To a solution of 2.6 g of 1,1-cyclopropanedicarboxylic acid, 2.4 ml of acetic anhydride, and 0.08 ml of sulfuric acid, 2 ml of acetone was added dropwise at 0 ° C. After reacting at 0 ° C. for 5 hours, 30 ml of water was added. A saturated aqueous sodium hydrogen carbonate solution was added until the pH reached 5, and then the precipitated solid was isolated by filtration to obtain 2.1 g of spirocyclopropane (SII-1).

(Synthesis Example II-2: Synthesis of Spirocyclopropane (SII-2))
Using cyclohexanone as a raw material, spirocyclopropane (SII-2) was obtained in the same manner as in Synthesis Example II-1.

(Synthesis Example II-3: Synthesis of Spirocyclopropane (SII-7))
7.81 g of N, N-dimethylbarbituric acid, 11.27 g of 1,2-dibromoethane, 13.82 g of potassium carbonate, 0.17 g of tetrabutylammonium hydrogen sulfate, and 70 ml of dimethylformamide were added and heated to reflux. After reacting for 4 hours, the reaction solution cooled to room temperature was filtered, and the filtrate was concentrated and purified by silica gel column chromatography to obtain 6.5 g of spirocyclopropane (SII-7).

(Synthesis Example II-4: Synthesis of Spirocyclopropane (SII-11))
Spirocyclopropane (SII-11) was obtained in the same manner as in Synthesis Example II-3 using N, N-diethylthiobarbituric acid as a raw material.

(Synthesis Example II-5: Synthesis of Spirocyclopropane (SII-14))
Spirocyclopropane (SII-14) was obtained in the same manner as in Synthesis Example II-3 using 1,2-dimethylpyrazolidine-3,5-dione as a raw material.

<Example>
2. Preparation of Electrolytic Solution To 1M LiPF ₆ ethylene carbonate (EC) / ethyl methyl carbonate (EMC) electrolytic solution having a volume ratio of 1: 2 and volume ratio of 1: 3 to the electrolytic solution obtained in Synthesis Example II-1. Propane compound (SII-1) was added in an amount of 0.05% by weight to prepare an electrolytic solution (Test No. II-101).
The electrolyte solution was prepared in the same manner by changing the type and amount of cyclopropane compound used as shown in the table (Test Nos. II-102 to II-111).

An electrolyte solution of 1M LiPF ₆ in ethylene carbonate / ethyl methyl carbonate was used as a comparative example. At this time, a comparative example was prepared by adding vinylene carbonate (VC), the following (RII-1), the following (RII-2), and the following cyclic acid anhydride (RII-3) under the same conditions as in the examples.

[Lithium secondary battery]
Lithium cobaltate mixture sheet (electrode capacity 1.5 mAh / cm ² : aluminum foil base, 13 mmφ) on the positive electrode, natural spherical graphite electrode sheet (electrode capacity 1.6 mAh / cm ² : Cu foil base, 14.5 mmφ) on the negative electrode Using a PP porous film (thickness 25 μm, 16 mmφ) as a separator, a lithium secondary battery for evaluation using an electrolytic solution shown in Table 2-1 below was produced.

<Evaluation of cycle performance (discharge capacity retention rate)>
Using a 2032 type battery produced by the above method, in a thermostatic chamber at 30 ° C., after charging at a constant current of 0.7 C until the battery voltage becomes 4.2 V, the current value is set to 0.06 mA at a constant voltage of 4.2 V. Or charging for 2 hours, and then 0.5C constant current discharge was performed until the battery voltage reached 2.75 V, resulting in one cycle. This was repeated until 300 cycles were reached.

<Low-temperature discharge rate evaluation (low-temperature discharge rate)>
Using the 2032 type battery produced by the above method, the discharge capacity ratio at −20 ° C. with respect to 30 ° C. was measured. In a constant temperature bath at 30 ° C, charge at a constant current of 0.1C until the battery voltage reaches 4.2V, then at 4.2V constant voltage, the current value becomes 0.06mA, or charge for 2 hours, then- In a constant temperature bath at 20 ° C., 0.1 C constant current discharge was performed until the 0 battery voltage became 2.75 V, and the discharge capacity was measured.

<Positive electrode load characteristics (load capacity retention ratio)>
The positive electrode that had been charged and discharged for 10 cycles in the cycle test was taken out, and the negative electrode was lithium, and a 2032 type battery was prepared using 1M LiPF ₆ ethylene carbonate / ethyl methyl carbonate volume ratio of 1 to 2 as the electrolyte. In a constant temperature bath at 30 ° C., after charging with a constant current of 0.7 C until the battery voltage becomes 4.2 V, the current value becomes 0.06 mA at a constant voltage of 4.2 V, or charging is performed for 2 hours, and then the battery is charged. 2C constant current discharge was performed until the voltage reached 2.75 V, and the discharge capacity and discharge curves were compared.

<Self-discharge characteristic evaluation (capacity remaining rate)>
Using the 2032 type battery produced by the above method, after charging at a constant current of 0.1 C until the battery voltage becomes 4.2 V at 0.4 mA in an environment of 30 ° C., the current value is 4.2 V constant voltage. The battery was charged at 0.06 mA or 2 hours, and 0.1 C constant current discharge was performed until the battery voltage reached 2.75 V, and the initial discharge capacity was measured. Furthermore, after charging at a constant current of 0.1 C until the battery voltage reaches 4.2 V, the current value becomes 0.06 mA at a constant voltage of 4.2 V, or after charging for 2 hours, Left under for 14 days. Then, after taking out to 30 degreeC environment, the discharge capacity when discharging on the same discharge conditions was measured.

<Evaluation of Cycleability at Li ₄ Ti ₅ O ₁₂ Negative Electrode (Discharge Capacity Maintenance Rate)>
The negative electrode was changed to a lithium titanate mixture sheet (electrode capacity 1.6 mAh / cm ² : aluminum foil base, 14.5 mmφ), and the battery voltage was 2. After charging at a constant current of 0.7 C until 8 V, the current value becomes 0.06 mA at a constant voltage of 2.8 V, or charging is performed for 2 hours, and then a constant current of 0.5 C is maintained until the battery voltage reaches 1.8 V. Current discharge was performed to make one cycle. This was repeated until 500 cycles were reached.

<Test results>
1. Discharge capacity maintenance ratio in the _300th cycle (DCMR ₃₀₀ : Discharge Capacity Maintaining Ratio)

(Note 1) Discharge capacity maintenance rate (%) =
(Discharge capacity at the 300th cycle / discharge capacity at the first cycle) × 100

As shown in Table 2-1, in the 2032 type non-aqueous electrolyte secondary batteries (test Nos. II-101 to II-113) of the examples, the 2032 type non-aqueous electrolyte secondary battery (test No. .. II-c11 to II-c16), it was confirmed that the capacity retention rate at the 300th cycle was superior. As a result, in the negative electrode according to the battery of the example, the spirocyclopropane compound added to the electrolyte receives electrons at the negative electrode and undergoes ring-opening polymerization to form a good SEI (Solid Electrolyte Interface) film on the negative electrode surface. This is considered to be due to the fact that the decomposition of the electrolytic solution was suppressed.
Further, even when LiMn ₂ O ₄ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ , and LiNi _0.33 Co _0.33 Mn _0.33 O ₂ are used as the positive electrode active material, they are similarly good. The discharge capacity retention rate was shown.

2. Low temperature discharge rate (LTDR: Low Temperature Discharging Rate)

(Note 2) Low temperature discharge rate (%) = (discharge capacity at −20 ° C./discharge capacity at 30 ° C.) × 100

As shown in Table 2-2, the 2032 type non-aqueous electrolyte secondary batteries (Test Nos. II-201 to II-209) of the examples are 2032 type non-aqueous electrolyte secondary batteries (Test No. .. II-c21 to II-c24) were confirmed to be superior in low-temperature discharge rate. As a result, lithium ions were stabilized in the SEI film formed on the negative electrode surface according to the battery of the example, the lithium ion conductivity in the film (SEI) was improved, and the interface migration resistance was reduced. Presumed to be due.

3. Load capacity maintenance ratio (LCCMR: Load-Carrying Capacity Maintaining Ratio)

(Note 3) Load capacity retention rate (%) = (2C discharge capacity / initial discharge capacity) × 100

As shown in Table 2-3, in the 2032 type non-aqueous electrolyte secondary batteries (Test Nos. II-301 to II-303) of Examples, the comparative examples (Test Nos. II-c31 to II-c36) were used. It was confirmed that the load characteristics were superior to the 2032 type nonaqueous electrolyte secondary battery. This result is presumed to be caused by the fact that a coating of the added spirocyclopropane compound was formed on the positive electrode surface of the battery of the example, the positive electrode was stabilized by the formed coating, and the resistance at the positive electrode interface was suppressed. Yes.
In addition, as shown in FIG. 3, the discharge curve in the secondary battery of Example (No. II-301) maintains a high voltage up to a high current region as compared with Comparative Example (No. II-c32). It was closer to the ideal.

4). Capacity remaining rate (RCR: Remaining Capacity Ratio)

(Note 4) Capacity remaining rate (%) = (discharge capacity after leaving for 14 days / initial discharge capacity) × 100

As shown in Table 2-4, the 2032 type non-aqueous electrolyte secondary batteries (Test Nos. II-401 to II-409) of the examples are 2032 type non-aqueous electrolyte secondary batteries (Test No. II-c41 to II-c44) were confirmed to have better self-discharge characteristics. This result is presumed to be attributable to the fact that the positive electrode was stabilized by the formed coating on the positive electrode surface of the battery of the example, and the self-decomposition of the positive electrode was suppressed.

5. Discharge capacity maintenance ratio at _500th cycle (DCMR ₅₀₀ : Discharge Capacity Maintaining Ratio)

(Note 5) Discharge capacity maintenance rate (%) =
(Discharge capacity at 500th cycle / discharge capacity at the first cycle) × 100

As shown in Table 2-5, the 2032 type non-aqueous electrolyte secondary batteries (Test Nos. II-501 and II-502) of the examples are 2032 type non-aqueous electrolyte secondary batteries (Test No. II-c51), it was confirmed that the capacity retention rate at the 500th cycle was superior. This result shows that the reduction proceeds at a potential higher than the insertion potential of lithium ions as in the case of the graphite negative electrode, a good SEI (Solid Electrolyte Interface) film is formed on the lithium titanate negative electrode, the electrolytic solution is decomposed, and This is considered to be due to suppression of electrode deterioration.
Further, even when LiMn ₂ O ₄ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ , and LiNi _0.33 Co _0.33 Mn _0.33 O ₂ are used as the positive electrode active material, they are similarly good. The discharge capacity retention rate was shown.

<Example III>
(Synthesis Example III-1: Synthesis of lactone-fused cyclopropane (SIII-1))
A solution of 1.89 g of NaBH _{4 in} 70 ml of tetrahydrofuran (THF) is cooled to 0 ° C., and a solution of 3-oxabicyclo (3.1.0) hexane-2,4-dione in 5.6 g of THF in 80 ml is added dropwise and reacted for 3 hours. It was. After completion of the reaction, 6N HCl was added until the pH reached 2, followed by extraction with t-butyl methyl ether and concentration. To the obtained organic substance, 100 ml of toluene and 0.2 g of p-toluenesulfonic acid were added and heated under reflux for 1 hour. After washing with water, extraction with t-butyl methyl ether, concentration, and purification by silica gel column chromatography, 3.1 g of a lactone-fused cyclopropane compound (SIII-1) was obtained.

(Synthesis Example III-2: Synthesis of Lactone-fused Cyclopropane (SIII-3))
A lactone-fused cyclopropane compound (SIII-3) is obtained in the same manner as in Synthesis Example III-1, using 1-methyl-3-oxabicyclo (3.1.0) hexane-2,4-dione as a raw material. It was.

(Synthesis Example III-3: Synthesis of lactone-fused cyclopropane (SIII-5))
To 5 g of cyclopropane, 100 ml of toluene and 0.2 g of p-toluenesulfonic acid were added and heated to reflux for 1 hour. After washing with water, extraction with t-butyl methyl ether, concentration, and purification by silica gel column chromatography, 3.8 g of a lactone-fused cyclopropane compound (SIII-5) was obtained.

(Synthesis Example III-4: Synthesis of Lactone-fused Cyclopropane (SIII-6))
To 6.63 g of allyl acetoacetate, 25 g of manganese (III) acetate, 8.47 g of copper (II) acetate, 9.15 g of potassium acetate, and 115 ml of acetic acid were added and reacted at 75 ° C. for 1 hour. After completion of the reaction, the reaction mixture was neutralized with aqueous sodium bicarbonate, extracted with ethyl acetate, concentrated and purified by silica gel column chromatography to obtain 2.8 g of a lactone-fused cyclopropane compound (SIII-6).

(Synthesis Example III-5: Synthesis of lactone-fused cyclopropane (SIII-7))
A lactone-fused cyclopropane compound (SIII-7) was obtained in the same manner as in Synthesis Example III-4, using allylmethylmalonate as a raw material.

(Synthesis Example III-6: Synthesis of Lactone-fused Cyclopropane (SIII-8))
Using allyl cyanoacetate as a raw material, a lactone-fused cyclopropane compound (SIII-8) was obtained in the same manner as in Synthesis Example III-5.

(Synthesis Example III-7: Synthesis of Lactone-fused Cyclopropane (SIII-10))
1.25 g of sodium hydride was added to 50 ml of THF and cooled in an ice bath. A solution obtained by adding 10 ml of THF to 8.8 g of diethyl malonate was added dropwise to the reaction vessel and stirred for 15 minutes. Thereafter, 8.15 g of α-bromobutenolide was added and the temperature was returned to room temperature, followed by stirring for 5 hours. After completion of the reaction, the reaction mixture was quenched with a saturated aqueous solution of ammonium chloride, extracted with ethyl acetate, concentrated and purified by silica gel column chromatography to obtain 6.5 g of a lactone-fused cyclopropane compound (SIII-10).

<Example>
2. Preparation of electrolyte solution Lactone contraction obtained in Synthesis Example III-1 was added to 1M LiPF ₆ ethylene carbonate (EC) / ethyl methyl carbonate (EMC) volume ratio 1 to 2 electrolyte solution and volume ratio 1 to 3 electrolyte solution. An electrolytic solution was prepared by adding 0.05% by mass of a cyclic cyclopropane compound (SIII-1) (Test No. III-101). Test No. For III-102 and below, electrolytes were similarly prepared (Test Nos. III-102 to III-114) by changing the types and addition amounts of the specific cyclopropane compounds used as shown in the table.

An electrolyte solution of 1M LiPF ₆ in ethylene carbonate / ethyl methyl carbonate was used as a comparative example. At this time, test no. A comparative example was prepared by adding vinylene carbonate (VC), the following (RIII-1), the following (RIII-2), and the following cyclic acid anhydride (RIII-3) under the same conditions as in III-101.

[Lithium secondary battery]

Lithium cobaltate mixture sheet (electrode capacity 1.5 mAh / cm ² : aluminum foil base, 13 mmφ) on the positive electrode, natural spherical graphite electrode sheet (electrode capacity 1.6 mAh / cm ² : Cu foil base, 14.5 mmφ) on the negative electrode Using a PP porous film (thickness 25 μm, 16 mmφ) as a separator, a lithium secondary battery for evaluation using an electrolytic solution shown in the following table was produced.

<Evaluation of cycle performance (discharge capacity retention rate)>
Using a 2032 type battery produced by the above method, in a thermostatic chamber at 30 ° C., after charging at a constant current of 0.7 C until the battery voltage becomes 4.2 V, the current value is set to 0.06 mA at a constant voltage of 4.2 V. Or charging for 2 hours, and then 0.5C constant current discharge was performed until the battery voltage reached 2.75 V, resulting in one cycle. This was repeated until 300 cycles were reached.

<Low-temperature discharge rate evaluation (low-temperature discharge rate)>
Using the 2032 type battery produced by the above method, the discharge capacity ratio at −20 ° C. with respect to 30 ° C. was measured. In a constant temperature bath at 30 ° C, charge at a constant current of 0.1C until the battery voltage reaches 4.2V, then at 4.2V constant voltage, the current value becomes 0.06mA, or charge for 2 hours, then- In a constant temperature bath at 20 ° C., 0.1 C constant current discharge was performed until the 0 battery voltage became 2.75 V, and the discharge capacity was measured.

<Positive electrode load characteristics (load capacity retention ratio)>
The positive electrode that had been charged and discharged for 10 cycles in the cycle test was taken out, and the negative electrode was made of lithium metal, and a 2032 type battery was prepared using 1M LiPF ₆ ethylene carbonate / ethyl methyl carbonate volume ratio of 1 to 2 as the electrolyte. . In a constant temperature bath at 30 ° C., after charging with a constant current of 0.7 C until the battery voltage becomes 4.2 V, the current value becomes 0.06 mA at a constant voltage of 4.2 V, or charging is performed for 2 hours, and then the battery is charged. 2C constant current discharge was performed until the voltage reached 2.75 V, and the discharge capacity and discharge curves were compared.

<Self-discharge characteristic evaluation (capacity remaining rate)>
Using the 2032 type battery produced by the above method, after charging at a constant current of 0.1 C until the battery voltage becomes 4.2 V at 0.4 mA in an environment of 30 ° C., the current value is 4.2 V constant voltage. The battery was charged at 0.06 mA or 2 hours, and 0.1 C constant current discharge was performed until the battery voltage reached 2.75 V, and the initial discharge capacity was measured. Furthermore, after charging at a constant current of 0.1 C until the battery voltage reaches 4.2 V, the current value becomes 0.06 mA at a constant voltage of 4.2 V, or after charging for 2 hours, Left under for 14 days. Then, after taking out to 30 degreeC environment, the discharge capacity when discharging on the same discharge conditions was measured.

<Evaluation of cycleability in Li ₄ Ti ₅ O ₁₂ negative electrode (discharge capacity retention rate)>
The negative electrode was changed to a lithium titanate mixture sheet (electrode capacity 1.6 mAh / cm ² : aluminum foil base, 14.5 mmφ), and the battery voltage was 2. After charging with a constant current of 0.7 C until 8 V, the current value becomes 0.06 mA at a constant voltage of 2.8 V, or charging is performed for 2 hours, and then a constant current of 0.5 C is maintained until the battery voltage reaches 1.8 V. Current discharge was performed to make one cycle. This was repeated until 500 cycles were reached.

<Test results>
1. Discharge capacity maintenance ratio in the _300th cycle (DCMR ₃₀₀ : Discharge Capacity Maintaining Ratio)

(Note 1) Discharge capacity maintenance rate (%) =
(Discharge capacity at the 300th cycle / discharge capacity at the first cycle) × 100

As shown in Table 3-1, in the 2032 type nonaqueous electrolyte secondary batteries (test Nos. III-101 to III-119) of the examples, the comparative examples (test Nos. III-c11 to III-c16) were used. It was confirmed that the capacity retention rate at the 300th cycle was superior to the 2032 type non-aqueous electrolyte secondary battery. As a result, in the negative electrode according to the battery of the example, the lactone-fused cyclopropane compound added to the electrolytic solution receives electrons at the negative electrode and undergoes ring-opening polymerization to form a good SEI (Solid Electrolyte Interface) film on the negative electrode surface. Thus, it is considered that the decomposition of the electrolytic solution is suppressed.
Further, even when LiMn ₂ O ₄ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ , and LiNi _0.33 Co _0.33 Mn _0.33 O ₂ are used as the positive electrode active material, they are similarly good. The discharge capacity retention rate was shown.

2. Low temperature discharge rate (LTDR: Low Temperature Discharging Rate)

(Note 2) Low temperature discharge rate (%) =
(Discharge capacity at −20 ° C./Discharge capacity at 30 ° C.) × 100

As shown in Table 3-2, in the 2032 type non-aqueous electrolyte secondary batteries of Examples (Test Nos. III-201 to III-210), the comparative examples (Test Nos. III-c21 to III-c24) were used. It was confirmed that the low-temperature discharge rate was superior to the 2032 type non-aqueous electrolyte secondary battery. As a result, lithium ions are stabilized by the lactone ring in the SEI film formed on the negative electrode surface according to the battery of the example, the lithium ion conductivity in the film (SEI) is improved, and the interface movement resistance is reduced. It is presumed to be caused by this.

3. Load capacity maintenance ratio (LCCMR: Load-Carrying Capacity Maintaining Ratio)

(Note 3) Load capacity maintenance rate (%) =
(2C discharge capacity / initial discharge capacity) × 100

As shown in Table 3-3, in the 2032 type non-aqueous electrolyte secondary batteries of the examples (Test Nos. III-301 to III-303), the comparative examples (Test Nos. III-c31 to III-c36) were used. It was confirmed that the load characteristics were superior to the 2032 type nonaqueous electrolyte secondary battery. This result is presumed to be due to the fact that a coating of lactone-fused cyclopropane was formed on the positive electrode surface of the battery of the example, the positive electrode was stabilized by the formed coating, and the resistance at the positive electrode interface was suppressed. .
Further, as shown in FIG. 4, the discharge curve in the secondary battery of Example (No. III-301) maintains a high voltage up to a high current region as compared with Comparative Example (No. III-c32). It was closer to the ideal.

4). Capacity remaining rate (RCR: Remaining Capacity Ratio)

(Note 4) Capacity remaining rate (%) = (discharge capacity after leaving for 14 days / initial discharge capacity) × 100

As shown in Table 3-4, in the 2032 type nonaqueous electrolyte secondary batteries of the examples (Test Nos. III-401 to III-410), the comparative examples (Test Nos. III-c41 to III-c44) were used. It was confirmed that the self-discharge characteristics were superior to the 2032 type nonaqueous electrolyte secondary battery. This result is presumed to be attributable to the fact that the positive electrode was stabilized by the formed coating on the positive electrode surface of the battery of the example, and the self-decomposition of the positive electrode was suppressed.

5. Discharge capacity maintenance ratio at _500th cycle (DCMR ₅₀₀ : Discharge Capacity Maintaining Ratio)

(Note 5) Discharge capacity maintenance rate (%) =
(Discharge capacity at 500th cycle / discharge capacity at the first cycle) × 100

As shown in Table 3-5, in the 2032 type non-aqueous electrolyte secondary battery of the examples (Test Nos. III-501 to III-504), the 2032 type non-aqueous electrolyte of the comparative example (Test No. III-c51) was used. It was confirmed that the capacity retention rate at the 500th cycle was superior to that of the electrolyte secondary battery. This result shows that the reduction proceeds at a potential higher than the insertion potential of lithium ions as in the case of the graphite negative electrode, a good SEI (Solid Electrolyte Interface) film is formed on the lithium titanate negative electrode, the electrolytic solution is decomposed, and This is considered to be due to suppression of electrode deterioration.
Further, even when LiMn ₂ O ₄ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ , and LiNi _0.33 Co _0.33 Mn _0.33 O ₂ are used as the positive electrode active material, they are similarly good. The discharge capacity retention rate was shown.

In the above examples, the lithium electrolyte of the present invention was used as a negative electrode, and a lithium / titanium oxide negative electrode or a carbon material negative electrode was developed. Excellent characteristics were exhibited in a battery using a combination of lithium manganese cobaltate, lithium cobaltate, and lithium manganate as a positive electrode. However, the electrolyte of the present invention is a metal or metal oxide negative electrode (preferably Si, Si oxide, Si / Si oxide, Sn capable of forming an alloy with lithium, which is being developed for higher capacity. , Sn oxide, SnB _x P _y O _z , Cu / Sn, and a plurality of these composites), and a battery using a composite of these metal or metal oxide and carbon material as a negative electrode, and / or 4.5V It can be presumed that the same excellent effect is exhibited even in a battery using a -5V class positive electrode.

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.
The present application is filed on Japanese Patent Application No. 2011-237789 filed in Japan on October 28, 2011, and Japanese Patent Application Nos. 2011-237990 and October 28, 2011 filed on October 28, 2011 in Japan. Claims priority based on Japanese Patent Application No. 2011-237991 filed in Japan, the contents of which are hereby incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Positive electrode collector 2 Positive electrode active material layer 3 Negative electrode collector 4 Negative electrode active material layer 5 Electrolyte 6 Operating means 7 Wiring 9 Separator 10 Lithium ion secondary battery 12 Separator 14 Positive electrode sheet 16 Negative electrode sheet 18 20 Insulating plate 22 Sealing plate 24 Positive electrode current collector 26 Gasket 28 Pressure sensitive valve element 30 Current interrupting element 100 Bottomed cylindrical lithium secondary battery

Claims (19)

1. At least selected from the group consisting of an electrolyte, a compound represented by the following formula (I-1), a compound represented by the following formula (II-1), and a compound represented by the following formula (III-1) An electrolyte solution for a non-aqueous secondary battery containing at least one cyclopropane compound in an organic solvent.
   

   

   (In the formula (I-1), R ¹¹ to R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. R ¹⁵ represents the number of carbon atoms. A substituent that may contain 1 to 7 oxygen atoms, nitrogen atoms, or sulfur atoms, L ¹¹ represents an alkylene group or a carbonyl group, and X represents an electron having a value of 0 or more in the σp value of Hammett's rule Indicates an attractive group.)
   (In the formula (II-1), R ²¹ to R ²⁴ each independently represents a hydrogen atom or a substituent. L ²¹ represents an atom that forms a ring structure together with the carbon atom of the carbonyl group and cyclopropyl group in the formula. Represents a group.)
   (In the formula (III-1), R ³¹ to R ³⁴ each independently represents a hydrogen atom or a substituent. L ³¹ represents an oxygen atom, —NR ³⁵ —, or a carbonyl group. L ³² represents an alkylene. A group, an oxygen atom, a sulfur atom, —SO ₂ —, or —NR ³⁵ —, wherein R ³⁵ represents an alkyl group or an aryl group, and n and m each independently represent 1 or 2.)
2. The electrolyte solution for a non-aqueous secondary battery according to claim 1, wherein the substituent X of the formula (I-1) represents a cyano group, an alkoxycarbonyl group, or a carbamoyl group.
3. The electrolyte solution for a non-aqueous secondary battery according to claim 1 or 2, wherein in the formula (I-1), R ¹¹ to R ¹⁴ are hydrogen atoms.
4. The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 to 3, wherein X in the formula (I-1) is a cyano group.
5. The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 to 4, wherein -L ¹¹ -R ^{15 in the} formula (I-1) is represented by -COOR ¹⁶ .
   ^{(R 16} is, a carbonyl group (-CO-), an ether group (-O-), a or an imino group ^{(-NR 17} - ^{.R 17} representing a) alkyl groups of 1-6 carbon atoms which may be interposed in Represents a hydrogen atom or an alkyl group.)
6. Formula (II-1) ^{ring L 21} is formed at the -CONR ²⁵ - (wherein ^{R 25} represents an alkyl group or an aryl group) non-aqueous secondary battery according to claim 1 comprising or -COO- Electrolyte.
7. The electrolyte solution for a non-aqueous secondary battery according to claim 1 or 6, wherein the compound represented by the formula (II-1) is a compound represented by the following formula (II-2).
   

   

   (Wherein R ²¹ to R ²⁴ have the same meaning as in formula (II-1). L ²² represents an atomic group forming a ring structure together with the carbon atoms of two carbonyl groups and a cyclopropyl group in the formula. )
8. The ring formed by L ²¹ in the formula (II-1) or the ring formed by L ²² in the formula (II-2) is a 5-membered ring or a 6-membered ring, The electrolyte solution for non-aqueous secondary batteries as described in the item.
9. The linking group formed by (L ³¹ ) n in the formula (III-1) is a carbonyloxy group, an amide group, or —COR ³⁶ — (R ³⁶ represents an alkylene group having 1 to 3 carbon atoms). The electrolyte solution for nonaqueous secondary batteries of 1.
10. 10. The electrolyte solution for a non-aqueous secondary battery according to claim 1, wherein L ³² in the formula (III-1) is an alkylene group, an oxygen atom, a sulfur atom, or —NR ³⁵ —.
11. The non-reactive compound according to any one of claims 1, 9, and 10, wherein the compound represented by the formula (III-1) is a compound represented by the following formula (III-2) or (III-3): Electrolyte for water secondary battery.
    

    

    (In the above formula, R ³¹ to R ³⁴ and L ³² have the same ^meaning as in formula (III-1).)
12. The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 and 9 to 11, wherein L ³² in the formula (III-1) is an alkylene group having 1 to 3 carbon atoms.
13. The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 and 9 to 12, wherein L ³² in the formula (III-1) is a methylene group.
14. The electrolyte for a non-aqueous secondary battery according to any one of claims 1 to 13, wherein the electrolyte is a lithium salt.
15. The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 to 14, wherein the cyclopropane compound is applied in a range of 0.005 to 20 mass% with respect to a total amount of the electrolyte solution.
16. The electrolyte solution for a non-aqueous secondary battery according to any one of claims 1 to 15, wherein a cyclic carbonate, a chain carbonate, or a cyclic ester is employed as the organic solvent.
17. A lithium secondary battery comprising the non-aqueous secondary battery electrolyte according to any one of claims 1 to 16, a positive electrode, and a negative electrode.
18. The secondary battery according to claim 17, wherein lithium titanate is applied as an active material of the negative electrode.
19. An electrolyte solution kit for a non-aqueous secondary battery using a mixture of a first agent and a second agent,
    The first agent contains an electrolyte, and the second agent contains a cyclopropane compound represented by the following formula (I-1), formula (II-1), or formula (III-1). Secondary battery electrolyte kit.
    

    

    (In the formula (I-1), R ¹¹ to R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a fluorine atom, a carbonyl group-containing group, or a cyano group. R ¹⁵ represents the number of carbon atoms. A substituent that may contain 1 to 7 oxygen atoms, nitrogen atoms, or sulfur atoms, L ¹¹ represents an alkylene group or a carbonyl group, and X represents an electron having a value of 0 or more in the σp value of Hammett's rule Indicates an attractive group.)
    (In the formula (II-1), R ²¹ to R ²⁴ each independently represents a hydrogen atom or a substituent. L ²¹ represents an atom that forms a ring structure together with the carbon atom of the carbonyl group and cyclopropyl group in the formula. Represents a group.)
    (In the formula (III-1), R ³¹ to R ³⁴ each independently represents a hydrogen atom or a substituent. L ³¹ represents an oxygen atom, —NR ³⁵ —, or a carbonyl group. L ³² represents an alkylene. A group, an oxygen atom, a sulfur atom, —SO ₂ —, or —NR ³⁵ —, wherein R ³⁵ represents an alkyl group or an aryl group, and n and m each independently represent 1 or 2.)

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